Influence of interlayer's thickness on strength of joints between LAS glass-ceramic and carbon/carbon composites

Surface modified carbon/carbon (C/C) composites were joined to Li₂CO₃-Al₂O₃ - SiO₂ (LAS) glass ceramic by hot pressing bonding using MgO-Al₂O₃-SiO₂ (MAS) glass with different thicknesses as the joining material. The effect of interlayer thickness on the joint strength was discussed. Microstructures and morphologies of the as-received joints and fractured surfaces were characterized by scanning electron microscope. The results indicated that the LAS glass was directly joined to the surface modified C/C composites at 1200°C, and the room-temperature shear strength of the joints was only 10 MPa, due to its poor wettability with base material. When the MAS glass was applied as interlayer, the joint shear strength increased at first and then decreased with the increase of the interlayer thickness. The maximum value of the shear strength reached 26.61 MPa when interlayer thickness was 80 μm.